A file quarantine technology is widely used in a sandbox, so that a modification made to a system by an application program inside the sandbox is quarantined and produces no influence on the system. For example, if a process of an application program inside a sandbox creates a file Virus.exe in a directory C:\Windows, the file Virus.exe can be detected by the process inside the sandbox but does not exist in the directory C:\Windows of the system. Current file quarantine technology has problems including high complexity or low security.